Kalwasser and Magnesium Question

[DonJuanAntwon]

Newbie reefer question. Got a 10 gallon nano reef that’s doing well. Started using kalwasser in my top off water to keep consistent Alk(9dkh)/Ca (440). Haven’t tested Magnesium in awhile because it was always consistently in 1300 range in the past. Tested it today and it was at 1000! I didn’t know kalwasser reduces magnesium until I read it on my magnesium dosing bottle. All the corals seem fine, fully opened etc. Would Kalwasser cause a 300ppm drops when used over a month period? Also how slow would you try to bring it back onto the 1300 range from 1000? Based on the bottle recommendations it seems I can do 10g twice a week? Thank you for any help/insight!

 

[Stigigemla]

With a 10 gallon reef i would only do waterchanges. In order not to schock the corals would I only change 1 gallon everytime.
But I would do it every day for two weeks maybe morning and evening and then check the value again. When the value is 1200 or higher You can change 2 gallons.
For such a small reef I would change 50% every week.

 

[Randy Holmes-Farley Verified Community Expert]

No, it would not cause such a drop in your system. The drop is either test error or a salinity decrease.

Just to clarify, the magnesium effect is not that kalkwasser uses magnesium (when added properly), it just doesn’t add any as it is consumed in precipitation of calcium carbonate.

 

[DonJuanAntwon]

No, it would not cause such a drop in your system. The drop is either test error or a salinity decrease.

Just to clarify, the magnesium effect is not that kalkwasser uses magnesium (when added properly), it just doesn’t add any as it is consumed in precipitation of calcium carbonate.

I’ve been testing my salinity consistently (1.205). Probably my most stable parameter. I’ll recalbrate my refractometer to make sure. I guess then it would be a test error.

 

[Randy Holmes-Farley Verified Community Expert]

I’ve been testing my salinity consistently (1.205). Probably my most stable parameter. I’ll recalbrate my refractometer to make sure. I guess then it would be a test error.

Magnesium test errors are very common. So common that I am not convinced that most folks should even be testing it, and rather should just use dosing methods that keep it in balance with calcium dosing.

 

[DonJuanAntwon]

Magnesium test errors are very common. So common that I am not convinced that most folks should even be testing it, and rather should just use dosing methods that keep it in balance with calcium dosing.

Very interesting. I really appreciate your insight! How would you recommend dosing it specifically?

 

[Maximitsurugi]

Magnesium test errors are very common. So common that I am not convinced that most folks should even be testing it, and rather should just use dosing methods that keep it in balance with calcium dosing.

Hey Randy, what’s the ratio of mag used in relation to Alk and Calcium. I’m dosing Kalk saturated but would like to know what the equivalent ratio would be. Thanks guy